*{
    margin: 0;
    padding: 0;
}
h1{
    text-align: center;
}
.box{
    margin: 0 auto;
    width: 100px;
    height:100px;
    background-color: red;
    text-align: center;
    line-height: 100px;
}
.cheng{
    margin: 0 auto;
    width: 100px;
    height: 100px;
    background-color:orangered;
    text-align: center;
    line-height: 100px;
}